Stackers are used in the printing industry to collect a flat, linear feed of cut sheets of paper, e.g. that are being feed over belts in a shingled configuration (i.e., overlapping with a slight overhang between successive sheet). In order to efficient handle and ship the sheets at the end of the printing and cutting process, they must be collected from the linear feed and stacked on top of each other. Typically, the individual sheets are stacked into a particular number of sheets per stack (e.g., 100 sheets per bundle). A typical stacker has a set of in feed belts that feed 25 the linear sheets into the machine and second set of belts that creates a break in the feed of sheets through the machine. As the linear sheets are passed over the second set of belts speeds they speed up after the desired number of sheets has passed over the second belts. This speeding up of the second belts creates a gap in the feed of linear sheets. This gap can be used to separate the sheets in a stack so that the stack has the desired number of sheets. However, this speeding up of the second belts, without additional handling, can cause problems in the processing of the sheets because they may become unaligned.
The present invention addresses this and other issues.